Holy Spirit
I myself did not know Him, but the One who sent Me to baptize with water said to me, ‘He on whom you see the Spirit descend and remain is the One who Baptizes with the Holy Spirit.’ John 1:33

On the last day of the festival, the great day, while Jesus was standing there, He cried out, “Let anyone who is thirsty come to Me, and let the one who believes in Me drink. As the Scripture has said, ‘Out of the believer’s heart shall flow rivers of Living Water.’” Now He said this about the Spirit, which believers in him were to receive; for as yet there was no Spirit because Jesus was not yet glorified. John 7:37-29
When Jesus had said this, He breathed on them and said to them, “Receive the Holy Spirit." John 20:22